Copper (Cu)-to-Cu bonding is a technique commonly used to form interconnects in electronic device structures. One drawback to conventional Cu-to-Cu bonding techniques is that any amount of misalignment between the Cu interconnect structures can lead to damaged/poor bonding between the structures, and potentially even to failure of the bond.
For example, the Cu interconnect structures can include complementary Cu pads that are brought together and bonded by way of a compression bond. If the pads are misaligned, e.g., the face of one pad is shifted to the left or to the right relative to the face of the other pad, then the bonding might be adversely affected. Specifically, the misalignment can cause a portion of the pads to not make contact with each other. Even worse, if the misalignment is severe enough, then the pads might encounter other structures when being brought together, further compromising the bond.
Since, in practice, some level of misalignment cannot be avoided, techniques that minimize the amount of misalignment and thus improve bonding quality and reliability would be desirable.